fix(core): fix ShellExecutionConfig spread and add ProjectRegistry save backoff

[mahimashanware]

Summary

Phase 1 of the dynamic extension plan directory resolution implementation. This PR addresses core infrastructure fixes required for stable configuration management.

Details

• ShellExecutionConfig Fix: Refactors setShellExecutionConfig in packages/core/src/config/config.ts to correctly spread and merge properties instead of overwriting the entire object.
• ProjectRegistry Robustness: Implements an exponential backoff loop in ProjectRegistry.save() to mitigate EBUSY and EPERM errors during high-frequency concurrent workspace registry updates.

Related Issues

Part of the effort to support scalable dynamic extension plan directories.

How to Validate

Run unit tests for config and project registry:

npm test -w @google/gemini-cli-core -- src/config/config.test.ts src/config/projectRegistry.test.ts

Pre-Merge Checklist

• Updated relevant documentation and README (if needed)
• Added/updated tests (if needed)
• Noted breaking changes (if any)
• Validated on required platforms/methods:
  • MacOS
    • npm run
  • Windows
    • npm run
  • Linux
    • npm run

Related to #24572.

[gemini-code-assist]

Summary of Changes

Hello, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request introduces crucial infrastructure fixes aimed at enhancing the stability and reliability of configuration management within the core module. It addresses a configuration merging issue in ShellExecutionConfig and significantly improves the robustness of ProjectRegistry's save operations by mitigating common file system errors, which is foundational for supporting dynamic extension plan directories.

Highlights

• ShellExecutionConfig Refactor: The setShellExecutionConfig method was refactored to correctly merge configuration properties using an object spread, preventing unintended overwrites.
• ProjectRegistry Robustness: An exponential backoff retry mechanism was implemented in ProjectRegistry.save() to handle EBUSY and EPERM errors during file rename operations, improving stability during concurrent access.

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[gemini-code-assist]

Code Review

This pull request simplifies the shell execution configuration update logic and implements a retry mechanism with exponential backoff for file renaming in the project registry to handle OS-level file locks. A new test case verifies this retry behavior. The review feedback highlights that the save method should rethrow errors after logging to ensure the caller is aware of persistence failures, preventing potential data inconsistency.

_{Note: Security Review did not run due to the size of the PR.}

[mahimashanware]

/gemini review

[gemini-code-assist]

Code Review

This pull request enhances the reliability of the project registry by implementing an exponential backoff retry mechanism for file renaming operations to handle OS-level locks (EBUSY/EPERM) and adding a cleanup step for temporary files. It also simplifies the setShellExecutionConfig method using spread syntax. Feedback was provided regarding a regression in setShellExecutionConfig where passing undefined values in the partial configuration will now overwrite existing settings, whereas the previous implementation preserved them using nullish coalescing.

[gemini-code-assist]

Code Review

This pull request refactors setShellExecutionConfig in config.ts to use a more concise merge strategy that ignores undefined values, supported by new unit tests. It also enhances ProjectRegistry.save by implementing a randomized temporary file path and an exponential backoff retry mechanism for EBUSY and EPERM errors during the rename operation. A review comment suggests using an explicit state variable to avoid redundant unlink calls in the finally block when the rename succeeds, preventing unnecessary system calls.

[mahimashanware]

/gemini review

[gemini-code-assist]

Code Review

This pull request enhances the Config and ProjectRegistry modules to improve concurrency, path normalization, and error handling. The setShellExecutionConfig method now supports partial updates while preserving defaults. ProjectRegistry has been refactored to use atomic file operations, randomized temporary files, and exponential backoff for retrying file locks. It also introduces JIT migration for path normalization and background cleanup of orphaned temporary files. I have no feedback to provide.

[gemini-code-assist]

Code Review

This pull request enhances the configuration and project registry systems for better reliability and concurrency handling. The setShellExecutionConfig method was updated to perform partial merges, ignoring null or undefined values to preserve existing settings. The ProjectRegistry now implements atomic file writes using the wx flag, exponential backoff for retries on file locks (EBUSY/EPERM), and background cleanup of orphaned temporary files. Additionally, path normalization was improved to use native realpaths for cross-platform consistency, and JIT migration was added for legacy registry data. I have no feedback to provide.

[ruomengz]

Looks good, thanks!